This invention relates to a process for assembling textile fibers into loose batts, and is more particularly concerned with a process suitable for high speed production of batts used in preparing high quality nonwoven fabrics.
Contractor and Hwang U.S. application Ser. No. 497,046, now U.S. Pat. No. 3,932,915, and Zafiroglu U.S. Pat. No. 3,797,074 disclose apparatus wherein staple fibers in batt form are fed to a toothed disperser roll which doffs the fibers into an air stream of high uniform velocity and low turbulence to form a thin stream of fibers that are then collected on a moving screen to form uniform webs suitable for further processing into nonwoven fabrics. The web-forming apparatus is capable of high speed operation when fed with uniform batts weighing many times the weight, in ounces per square yard, of the uniform webs produced. Suitable feed batts can be prepared by cross-lapping a plurality of webs formed by a carding or air-laydown machine, but production rates which can be achieved with conventional cross-lappers are limited. Apparatus has not been available for producing batts of the desired basis weight and uniformity without the use of cross-lappers.
The batt-forming apparatus used in the present invention makes possible high-speed production of heavy batts of improved uniformity. Batts weighing 10 to 150 ounces per square yard can be produced without cross-lapping. Its operation, in producing batts of the required uniformity and basis weight, is characterized by lack of sensitivity to the type of fiber, e.g., denier per filament, staple length, crimp and composition. The batt-forming apparatus can be coupled to the web-forming apparatus to obtain high production rates from the combination.